Conventional C-clamps are used in a variety of ways by mechanics, machinists, welders, constructors, repairers and the like. Each clamp normally provides two clamping surfaces, one fixed and the other adjustable. The fixed surface is located at one end of a C-shaped rigid frame and the adjustable surface is positioned on the other end of the frame by a threaded rod. Rotating the rod varies the distance between the clamping surfaces to accommodate various sizes of workpieces and to apply or release a clamping force.
While widely useful, the lack of flexibility of use offered by the basic C-clamp has led to efforts to provide more versatile clamping arrangements. For example, U.S. Pat. No. 1,352,647 to Benton shows two C-clamps connected at the end of their shanks by a bolt, thereby affording a double clamp adjustable to a variety of positions.
U.S. Pat. No. 2,636,527 to Schiemann discloses the use of so-called male and female C-clamps fastened together with set screws to provide a number of different clamping arrangements.
U.S. Pat. No. 4,363,475 to McCarty illustrates another C-clamp structure in which a C-clamp is provided with a pair of holes cooperating with holes on a plate 19 to orient the C-clamp in one of a number of possible positions.
The above C-clamp structures and others in the prior art all fail to provide a clamping arrangement using C-clamps versatile enough to hold a great variety of workpieces in many desired relationships.